Elachista demogenes is a moth in the family Elachistidae. It was described by Edward Meyrick in 1897. It is found in Australia, where it has been recorded from South Australia.[1]
The wingspan is 7–8 mm. The forewings are pale grey, irrorated with dark fuscous, sometimes with a suffusion of black irroration towards the dorsum anteriorly and toward the costa posteriorly. The plical and second discal stigmata are black. The hindwings are grey.[2]
The species was described in the family Elachistidae, but was excluded from this family in a later study.[3]